It seemed like I was using the same pattern for both long johns and outerwear fleece pants. The main differences were just the weight of the fabric and details such as pockets and zippers. In general, I realized that a pair of close-fitting thermal stretch pants could handle most any cold-weather activity I could dream up with just a few modifications. This is a master pattern detailing three popular options to offer people ways to keep their legs warm for whatever they do.

View A–The Basic: Pullover with elastic/drawstring waist. Wraparound legs with no outseam. Simple hemmed cuffs.

View B–Wind-Shell Front: Woven fabric overlays the fleece on the front half only with knee pleats for flexibility. Elastic/drawstring waist, optional zippered front pockets, simple hemmed cuffs.

View C–Side Zips: Full length, separating side zippers with interior zipper flaps. Waist and cuff tabs, elastic waist, optional zippered front pockets.

• Stretch Fleece - 4-way stretch knits (containing Spandex) and having at least 50% stretch both crosswise and up and down are recommended. Examples are Polartec Powerstretch and Polartec 200S.
  
• View B Shell Fabric - A lightweight (1.0 to 2.5 oz./yd2) and tightly woven taffeta, ripstop or similar fabric. Nylon or polyester is recommended. Should generally be uncoated, wind resistant and breathable.
  
• Optional Pocket Lining Fabric - Use either the same view B shell fabric above or a lightweight, non-stretchy and nonabsorbent mesh.